Automatic traffic signal



. NOV. 5,1929. PAGE 1,734,228

AUTOMATIC TRAFFIC SIGNAL Filed Dec. 29, 1928 INVENTOR RA NK PA q 5 Patented Nov. 5, 1929 FRANK PAGE, OF VANCOUVER, BRITISH COLUMBIA, CANADA AUTOMATIC TRAFFIC SIGNAL Application filed December 29, 1928,

My invention relates to improvements in automatic trafiic signals which are particularly adapted to be fitted at street crossings remote from city areas, but where the trafiic is heavy. The objects of the invention are to provide means whereby a vehicle driven along one road towards a crossing will cause a signal to be displayed thereat as a warning of the vehicles approach to drivers of other vehicles travelling on the intersecting road toward such crossing, and to provide that such signal shall be removed from display after the actuating vehicle has passed the crossing or at any suitable period.

The invention consists essentially of a base adapted to be set in the centre of the crossing having one or more normally retracted signals and a trip lever remote from the crossing operatively connected to each signal, which when depressed by the front wheels of a passing car will cause the signal to be brought into a position of display and subsequently withdrawn therefrom, as will be more fully described in the following specification and shown in the accompanying drawings, in

which Fig. 1 is a-plan showing the invention at a street crossing.

Fig. 2 is a sectional view of one of the depression plates through which a signal is actuated.

Fig. 3 is a sectional view of the silent policeman at the intersection showing one of the signals in retracted position.

Fig. 4 is a sectional view of the signal actuating means.

In the drawings like characters of reference indicate corresponding parts in each figure.

The numeral 1, see Figure 1, indicates an intersection of two roads 2 and 3, in the centre of which intersection or crossing a silent policeman generally indicated by the numeral 4: is installed. The silent policeman 4L consists of a casing 5 preferably projecting upwards above the surface of the crossing and having inclined side walls 6 and a relatively flat top wall 7 in which are formed slots 8 according to the number of branches to the crossing, viz, where two roads inter- Serial No. 329,266.

sect, tour slots will be provided. Suitably mounted upon a hinge pin 9 below each of the slots 8 is a semaphore or signal 10 having a narrow strip 11 on its uppermost edge which is adapted to cover the slot when the signal is in retracted position. The signals may be provided with suitable indicia, such as Stop or Slow to indicate to drivers approaching them of the approach of others from the cross street.

Each signal 10 is fitted with a pin 12 to which the outer end of a rod 13 is connected. At a point on each road remote from the crossing is an elongated casing 14 which extends transversely of the road and is of such a length as to be traversed by the wheels of one or both sides of a vehicle driven along the proper side of a road approaching the signals. The upper wall of the casing is provided with an elongated opening 15 into which a hinged plate 16 having a downwardly curved lip17 at its free edge is fitted. EX- tending downwardly from the plate 16, adjacent its hinge 18, is an arm 19, which is engaged by a compression spring 20 for the purpose of raising the plate to inclined or normal position as shown in Figure 2, and is connected at its outer end to a rod or wire 21 which extends througha suitable conduit 22 leading to the base of the silent policeman 4t.

Within the base of the casing 5 is a horizontally mounted dash pot 23, see Figure 4, consisting-of a cylinder 2tl1aving a head 25 fitted with a suitable gland a hollow piston rod 26 having a piston 27 which is adapted to be returned to its innermost position by a compression spring 28. The cylinder 24 is provided with a communicating passage 29 having a needle valve'30 by which the flow of fluid fromone side of the piston to the other is controlled. Fitted to the outer end (if the hollow piston rod 26 is a head 31 having a forwardly inclined arm 32 and an eyed projection 33 which latter forms a pivotal connection with the rod 13 controlling one of the signals 10. An upstanding bracket 34 having an arm 35 provided with an eye 36 is mounted on the base of the casing at in front of each dash pot 23 and extending through 1 the eye and into the hollow piston rod 26 is a rod 37.

The rod 37 is fitted with a fixed collar 38 which is in the form of a short truncated cone and is in turn connected to the piston head 31 by a plurality of tension springs 39 of greater strength than the compression spring 28 so as to draw the piston slowly outwards when tensioned against the fluid resistance within the cylinder.

Mounted upon an olfset arm 40 extending from the bracket 34; is a swinging latch 41 having a limited movement and a dog at one end as at 12 which is adapted to be raised by and subsequently engage the collar 38 to hold it in extended position, the opposite end of the latch projects beyond its fulcrum as at 43 and is adapted to be depressed by the inclined arm 32 on the piston head 31 as it is moved to its most forward position by the tension springs 39. The wire 21 from the arm 19 of the plate 16 is connected at its innermost end to the rod 37 to complete the operating connection between the said plate and its signal 10.

Having thus described the several parts of my invention I will now briefly explain its function.

As a car approaches the crossing its wheels pass over the hinged depression plate 16 causing it to be lowered to the level of the top wall of the casing 14 and through the arm 19 to draw the wire 21 against the direction of the car travel. The wire 21 transmits its endwise motion to the rod 37 and a collar 38 against the tension of springs 39 until the rod 37 becomes held in outward position by a latch arm 11 engaging the collar 38. The tension of the springs 39 then draws the piston 27 slowly forwards against the spring 28, and gradually displaces the fluid in the cylinder 24: through the communicating passage 29 and needle valve 30 from one side of the piston to the other, simultaneously imparting a radial motion to the signal 10 which is facing the intersecting road to the right. As soon as the signal is raised to its full position of display, the inclined arm 32 trips the latch arm 41 and releases the collar 38, thus allowing the rod 37 to return to its innermost position within the piston rod, the spring 28 then slowly moves the piston 27 to the position shown in Figure 4 and causes the signal 10 to be removed from display. It will be obvious that by increasing the strength of the springs 28 and 39 to compensate for the weight of the hinged plate 16, that the spring 20 can be dispensed with, in which case the said plate would remain depressed until the rear wheels of the car which had depressed it had passed thereover.

\Vhat I claim as my invention is In a signalling system for street crossings,

signalling element operatively vconnected ,to

of December, 1928.

FRANK PAGE. 

